RGraph: Javascript charts and graph library - You don't need to spend a lot of money to get attractive charts

You don't need to spend a lot of money to get good looking charts, as the chart to the right shows. It's a Bar, Line and Pie chart combination, complete with Line and Pie chart tooltips.

There are two canvas tags - one for the Line/Bar chart and the other for the Pie chart. The Pie chart canvas is positioned over the other by using CSS and relative/absolute positioning.